<app-hero-detail [hero] = "selectedHero"></app-hero-detail>
<ul class="heroes">
  <li 
    *ngFor = "let hero of heroes"
    >
    <a routerLink="/detail/{{hero.id}}">
      <span class="badge">{{hero.id}}</span> {{hero.name}}
    </a>
  </li>
</ul>